Most baby teeth don’t start erupting until around 6-9 months of age and they can appear tiny and insignificant. Baby teeth last a lot longer. The front teeth may fall out at age 6 or 7, but the backs ones stay until you’re 12 or 13. They are also really important for guiding the development and positioning of the secondary teeth. Enamel is the protective outer layer of the tooth. In some kids they don’t form properly, leaving them to tooth sensitivity and decay. But the bigge ..